A candidate backed by former Kenyan Deputy President Rigathi Gachagua has won the Ol Kalou parliamentary by-election, in a result that analysts say could reshape the political landscape in the Mount Kenya region ahead of the 2027 General Election.

Sammy Kamau Ngotho of the Democracy for Citizens Party (DCP) defeated the ruling United Democratic Alliance (UDA) candidate, Samuel Muchina Nyaga, in a contest widely viewed as a test of political influence between President William Ruto and his former deputy.

The victory marks one of the biggest electoral successes for Mr Gachagua since his fallout with President Ruto and the subsequent launch of his new political movement.

The by-election was called following the death of Ol Kalou MP David Kiaraho earlier this year. Although nine candidates were on the ballot, the race quickly evolved into a contest between the governing UDA and Mr Gachagua's DCP.

Throughout the campaign, both sides invested significant political capital in the constituency, with senior leaders holding rallies and appealing to voters. For President Ruto, retaining the seat would have reinforced UDA's dominance in the Mount Kenya region, traditionally regarded as one of its strongest support bases.

For Mr Gachagua, however, the election represented an opportunity to demonstrate that he continues to command considerable support despite his departure from government.

The campaign was also marked by political tensions. Mr Gachagua accused state agencies and electoral officials of attempting to influence the outcome, allegations rejected by the ruling party. Electoral authorities maintained that the vote would be conducted in accordance with the law.

Political observers say the outcome is likely to strengthen Mr Gachagua's position as an emerging opposition figure while raising fresh questions about UDA's grip on the vote-rich Mount Kenya region.

Although a single parliamentary seat is unlikely to alter the balance of power in Parliament, the symbolic importance of the result could resonate far beyond Nyandarua County as political alliances begin to take shape ahead of Kenya's next general election.

The Ol Kalou by-election is expected to be closely analysed by both government and opposition strategists as an early indication of shifting political loyalties in one of Kenya's most influential voting blocs.